1. Field of the Invention
The present invention relates to a filter system for a hard disk drive.
2. Description of Related Art
Hard disk drives contain magnetic heads which magnetize and sense the magnetic fields of adjacent magnetic disks. The introduction of contaminants such as dust or water into the drive unit may induce errors during the operation of the disk drive. It would be desirable to absolutely seal the disk drive to prevent foreign matter from entering the inner cavity of the drive. Unfortunately, defects occur in the manufacturing or subsequent use of the disk drive which degrade the seal. For this reason most commercially available hard disk drives contain filter systems that remove contaminants that enter the drive unit. Such filter systems typically have a dedicated opening or openings through which ambient air may flow into the disk drive. A filter(s) is typically placed in fluid communication with the opening to capture any contaminants. The opening typically requires an additional manufacturing step which increases the cost of the drive. It would be desirable to have a disk drive which can "breath" without having any openings in the drive.
A filter system for a hard disk drive must be capable of removing both dust and water particles that may enter the drive unit. Additionally, it is also desirable to have a second filter system that removes any contaminants that were not captured by the primary filters, trapped in the drive during assembly, or that enter the cavity through a secondary opening. These contaminants may include acidic gases that are released by components located within the drive. It would be desirable to have a filter system within the disk drive which can remove different types of contaminants within the drive. It would also be desirable to have a multi-function filter system that can fit within a hard disk drive which meets the specifications promulgated by the Personal Computer Memory Card International Association (PCMCIA).